The transformer oil which is petroleum based has been used for the transformer as the dielectric media. It acts as a coolant in transformer. Soil will be contaminated when a mineral oil spill takes place. In future there will be scarcity of mineral oil as it is extracted from petroleum products. Now a day’s Synthetic oil and natural esters are the alternativesfor transformer oil because of they are biodegradable. Oxidation stability of ester oil must be improved as they are very poor in oxidation stability.In this paper, Investigation is carried out to study the performance of Indigenous oil. The different properties wereInvestigated i.e. Viscosity, breakdown voltage, Flash point. The comparison of properties has been made among mineral oil, Indigenous oil and vegetable oil without additives and degassing and BDV of Indigenous oil is investigated by adding additive like DBPC and by degassing. The Indigenous oil is code named as DM and Indigenous oil with DBPC is codenamed as DM1. The result shows that Indigenous oil is better compared to mineral oil and BDV values are improved by adding antioxidant and also by degasification.